Answer
See below
Work Step by Step
We obtain $B=\begin{bmatrix}
b_1,b_2
\end{bmatrix}=\begin{bmatrix}
-2 &-4\\-6&-6\\3&0\\-1&0\\-2 &1
\end{bmatrix}$
The row vectors of $B$ is:
$a_1=\begin{bmatrix}
-2 &-4
\end{bmatrix}\\
a_2=\begin{bmatrix}
-6 &-6
\end{bmatrix}\\
a_3=\begin{bmatrix}
3 &0
\end{bmatrix}\\
a_4=\begin{bmatrix}
-1 &0
\end{bmatrix}\\
a_5=\begin{bmatrix}
-2 & 1
\end{bmatrix}$
